This invention relates to laser light scanning using a holographic diffraction disc (also called a "spinner" or "scanner"). Specifically it provides for a means to correct for the effect of the displacement of the diffracted laser beam caused by "wobble" of a tilted holographic spinner disc. "Wobble" is a phenomenon resulting from misalignment between the spinner disc and its axis of rotation such that a normal to the plane of the disc forms a small angle with the axis of rotation of the disc. The invention finds utility in a scanning system using a laser beam for the writing of information on a photoconductive or other writing surface.